The invention generally relates to nasal breathing masks.
Nasal breathing masks are used, inter alia, to supply respiratory air primarily for therapeutic purposes, such as for example for treating disturbed sleep accompanied by apnea.
Conventional breathing masks comprise a partially elastic mask part, which is suitably anatomically shaped to bear against the region of the mouth and/or nose of the patient, and a mask-holding part, which is connected to the mask part and to which holding straps of the breathing mask are attached, so that the mask can be pressed onto the nose and/or mouth, the holding straps being guided behind the back of the head. The respiratory air can be supplied through a breathing hose via a hose connection on the mask-holding part. The respiratory air is generally taken from a unit which generates superatmospheric pressure.
WO 99/65554, in the name of the applicant, has disclosed a nasal breathing mask having a mask part and a mask-holding part which is connected thereto and to at least one strap for positioning the breathing mask on the nose of a user and which at the top end is connected to an elongate tube, which in turn is connected to a hose connection for a breathing hose and on which a forehead plate, which is connected to a forehead-plate mount, is axially adjustable. In this mask, the forehead-plate mount has a sleeve which can be displaced in the axial direction on the elongate tube. In order, in this breathing mask which is known from the prior art, on the one hand to ensure that the axial adjustability is possible, so that the distance between the forehead plate and the mask part can be adapted as a function of the anatomy of the user, and, on the other hand, to maintain the axial height of the forehead plate which is then set if the patient moves while sleeping, grooves which run around the inner surface of the sleeve are provided, into which grooves corresponding O-rings are inserted. To simultaneously achieve easy adjustability and nevertheless a secure position, a slight surface pressure between the groove of the sleeve, the O-ring mounted therein and the tube is advantageous.
To achieve a slight surface pressure, however, relatively thick O-rings are required, for which purpose in turn relatively large grooves are required in the sleeve. However, such grooves cannot be produced by means of collapsible cores during the injection-molding operation, since, for production and design reasons, such cords cannot be made large enough.
However, the use of relatively small O-rings has the associated drawback that, in constant use, they tend to migrate out of the groove in the sleeve, so that as a result the easy adjustability is lost and the secure position of the axial height which has been set is also not ensured when the breathing mask is being used while the user is asleep. Having to constantly thread the O-rings back in for reuse leads to a considerable reduction in the operating comfort of a breathing mask of this type.
Working on the basis of these drawbacks which are known from the prior art, the present invention is based on the object of providing a nasal breathing mask of the generic type which ensures that it is held securely and functions perfectly even for users who sleep restlessly, which provides minimum possible restriction to the freedom of movement of the user and which makes adjusting the distance between the forehead plate and the mask part in order to adapt to the anatomy of the user firstly easy to manage and secondly securely positioned after it has been set.
According to the invention, this object is achieved by means of a breathing mask as claimed herein.
Advantageous configurations of the breathing mask according to the invention are given in the dependent claims.
The nasal breathing mask according to the invention offers the advantage that ease of handling during the axial adjustment of the forehead-plate mount on the tube is ensured, so that the distance between the forehead-plate and the mask part can be individually adapted to every patient and the anatomy of every patient.
At the same time, the latching or clamping mechanism between the forehead-plate mount and the tube ensures that, once set, the axial height of the forehead plate can no longer change.
In a preferred embodiment, the forehead-plate mount is designed in the manner of a U-shaped collar. This collar is open toward the front, i.e. in the side remote from the user, and has recesses on the inside which run parallel to one another in the axial direction and annularly in the circumferential direction.
Annularly encircling ribs, which are of complementary design with respect to the recesses, are formed integrally on the circumferential surface of the tube, so that they can be pushed releasably into the recesses. The engagement between the recesses and the ribs, which are preferably in each case arranged equidistantly, provides the possibility of axially securing the forehead-plate mount with respect to the tube at the fixed distances between the recesses and the ribs.
The collar advantageously has an internal diameter which is slightly smaller than the external diameter of the ribbed tube, so that the forehead-plate mount can be latched onto the tube in a releasable manner. This undersizing alone allows a sufficient latching connection between these two components, so that initial secure positioning is provided when the distance between the forehead plate and the mask part is being adapted.
When the axial height which is to be set has been determined as a function of the anatomy of the patient, the position of the device can be finally fixed securely as a result of the possibility of a latching clip, on the side of the forehead-plate mount opposite from the user, being latchable onto the forehead-plate mount in a releasable manner.
According to an advantageous configuration of the invention, the latching clip has two limbs which are under a prestress. At their respective ends, the limbs are provided with a lug which can engage into an opening arranged in the forehead plate. This latching into place is effected by pressing the limbs together, against the prestress, introducing the lugs into the respective openings, so that then the prestress allows the lugs to latch into the openings.
According to another advantageous configuration of the invention, the latching clip also has ribs on its inner side toward the user, i.e. toward the tube, which ribs can be received in a complementary manner in the spaces which are formed by the ribs of the tube, so that in this respect too a sufficiently secure position is provided.
The latching clip clamps the tube against the forehead-plate mount and prevents the possibility of this mount unintentionally becoming detached while the user is asleep.
To facilitate the introduction of the limbs into the openings in the forehead plate, the limbs can be received in guides which are formed on the outer flanks of the U-shaped collar of the forehead-plate mount.
To prevent the possibility of the tube twisting radially in the forehead-plate mount, according to the invention the forehead-plate mount may, on the opposite side from its opening, have a groove which runs in the axial direction and in which a corresponding axial rib which is formed integrally on the tube can be received axially.
In an advantageous configuration of the invention, the forehead-plate mount and the forehead plate may be of integral design.
According to another advantageous configuration of the invention, between the mask part and the forehead plate there is provided a region of the tube which is designed and arranged in such a way that the mask part can be moved toward the user with respect to the forehead-plate mount. An inventive design of the tube of this type provides a further possibility of adjustment with respect to the varying anatomies of the patients, so that the distance between the forehead and the nose in the frontal plane of the patient can be compensated for. A region of this type may, for example, be of flexible design and consist in a reduction in the wall thickness of the tube, so that a greater degree of flexibility, in particular flexural elasticity, is offered compared to the remaining tube body of greater wall thickness.
According to the invention, this region can also be produced by means of at least one ball joint, preferably by means of two ball joints, so that the mask part can be moved toward the nose of the user, with two degrees of freedom being created by the ball joints.
Another design according to the invention can be effected by configuring the more flexible region in the form of bellows, in the manner of a bendable drinking straw.
According to an advantageous configuration of the invention, a flexible, in particular flexurally elastic, hose is arranged between the mask-holding part and the tube. Advantageously, a tube connection piece, over which, as also over the tube, the hose can be pushed, is formed integrally on the mask-holding part. In this case, it is advantageous if both the tube connection piece and the tube have a circumferential sealing lip or a sealing bead, over which the hose can be pushed so as to form a connection which can be released again but is sufficiently airtight and rigid.
When using a flexible hose, according to the invention a distance between the tube connection piece of the mask-holding part and the tube of a few millimeters, for example of 2 mm, is sufficient to provide sufficient mobility to compensate for the anatomies which exist.
On account of the hygiene and cleanability which have to be considered with a nasal breathing mask of this type, according to a further advantageous configuration of the invention all the components of the breathing mask are made from silicone.